Viewfinders of varying degrees of sophistication have been used on cameras for many years. The simplest varieties usually provide some sort of frame or reticle which aids the user of the camera during composition of a scene prior to capture of an image. More complex cameras may include mechanical or electronic masking arrangements for changing the field of view to show different aspect ratios to be used for images captured. Electrically actuated analog and digital displays have been provided at edges of the field of view to indicate conditions such as light level, flash readiness, lens setting and the like.
Holographic viewfinder displays have been used in which a holographic element is illuminated in selected areas to produce fixed images. For example, separate fixed images might indicate messages such as film speed or "low light" or "flash needed." Or, separate fixed images might be provided to be illuminated as each frame is exposed. A difficulty with known holographic viewfinder displays is that the images which can be displayed are fixed in time, which severely limits the size, number and/or brightness of images which can be provided in the small field of view of a typical viewfinder. Thus, a desirable improvement would be a viewfinder with a holographic display which can be readily modified to suit the user's desires or updated to reflect changes in photographic conditions.